Columbia Funds Series Trust 425Business combination disclosure

Filing by Columbia Funds Series Trust pursuant to Rule 425 under the Securities Act of 1933, and deemed filed under Rule 14a-12(b) under the Securities Exchange Act of 1934.

Subject Company:

BMO Funds, Inc.

(SEC File No. 811-58433)

COLUMBIA THREADNEEDLE – BMO FUND MERGER, NEW FUND LAUNCH DETAILS TRANCHE 1

As part of the Bank of Montreal integration, we previously announced our intent to launch five new Columbia funds into which several BMO funds will merge. The new Columbia funds will mirror the investment strategies of merging BMO funds and adopt standard Columbia fund contracts and fee schedules. The funds below are part of our Tranche 1 launch and merger, which were voted on and approved by shareholders. The following acquired funds are expected to merge into their corresponding acquiring at the close of business on December 10, 2021.

Refer to the attached spreadsheet for detailed fund information.

Pricing & Merger Methodology

Firms that trade via NSCC:

For institutional and broker/dealer use only. This material has not been filed with FINRA and may not be shown, quoted to, or used with, members of the general public.

November 24, 2021

Networking – Activity Files

A reminder about merger-related distributions

Please have your clients read and consider investment objectives, risks, charges, and expenses carefully before investing. Remind them to contact you or visit columbiathreadneedleus.com for a prospectus or summary prospectus, which contains this and other important information about the fund.

If you have any questions about this information, please call Intermediary Services at 800.441.4020.

Investment products offered through Columbia Management Investment Distributors, Inc., member FINRA. Advisory services provided by Columbia Management Investment Advisers, LLC.

Columbia Threadneedle Investments (Columbia Threadneedle) is the global brand name of the Columbia and Threadneedle group of companies.

For institutional and broker/dealer use only. This material has not been filed with FINRA and may not be shown, quoted to, or used with, members of the general public.

CUSIP identifiers have been provided by CUSIP Global Services, managed on behalf of the American Bankers Association by Standard & Poor’s Financial Services, LLC, and are not for use or dissemination in a manner that would serve as a substitute for any CUSIP service.

The CUSIP Database, ^© 2011 American Bankers Association. “CUSIP” is a registered trademark of the American Bankers Association.

For institutional and broker/dealer use only. This material has not been filed with FINRA and may not be shown, quoted to, or used with, members of the general public.

^© 2021 Columbia Management Investment Advisers, LLC. All rights reserved.

Columbia Management Investment Distributors, Inc.

290 Congress Street, Boston, MA 02110-2804

columbiathreadneedle.com/us

800.426.3750

                                                                 3905547 (11/21)

115 S LaSalle St.

11^th Floor

Chicago, IL 60603

In prior communications, we shared that the BMO Funds Board of Directors approved the planned reorganizations of several BMO Funds and that shareholder proxy statements for each reorganization were filed and mailed in October. Shareholders of each Merging Fund received a combined proxy statement and ballot that included additional information about the shareholder meeting, the plan of reorganization and the new investment advisory or subadvisory agreements.

A joint meeting of shareholders of the Merging Funds was held on November 23, 2021 at which they were asked to consider and vote on a plan with respect to their Merging Fund. Shareholders of the Pyrford Fund and LGM Fund were also asked to consider and vote on new subadvisory agreements.

Shareholders of the BMO Pyrford International Stock Fund approved a new investment subadvisory agreement between BMO Asset Management Corp. and Pyrford International Ltd. which took effect on or about November 24, 2021. Shareholders of the BMO LGM Emerging Markets Fund approved a new investment subadvisory agreement between BMO Asset Management Corp. and LGM Investments Ltd. which took effect on or about November 24, 2021.

The following mergers were approved by shareholders of each Merging Fund, and Merging Fund shareholders for each share class will receive shares of the corresponding share class of the Acquiring Fund as set forth in the table below. These reorganizations are expected to close on or about December 10, 2021 and in anticipation of these reorganizations, the last day for purchases, exchanges and redemptions will be December 9, 2021.

* Denotes newly-registered funds created to retain the corresponding BMO Fund; all other Columbia Funds are currently in operation.

FOR FINANCIAL PROFESSIONAL USE ONLY

115 S LaSalle St.

11^th Floor

Chicago, IL 60603

Shareholders of each Merging Fund will become shareholders of the corresponding Acquiring Fund, receiving shares of the Acquiring Fund equal in value to the shares of the Merging Fund held by the shareholders prior to the applicable reorganization. The reorganizations themselves are not expected to result in the recognition of gain or loss by the Merging Fund or its shareholders for federal tax purposes. Shareholders of the Merging Funds and the Acquiring Funds will not bear the costs of the reorganizations. Certain Merging Funds will reposition their portfolios prior to the reorganizations. Any resulting net capital gains will be distributed to shareholders in early December.

Both capital gains as well as ordinary income distributions will be paid in accordance with the applicable dates below.

The table below shows the additional reorganizations that were approved by the BMO Funds Board of Directors. At the joint meeting of shareholders held on November 23, 2021, shareholders of each of the BMO Dividend Income Fund, BMO Large-Cap Value Fund, BMO Mid-Cap Growth Fund, BMO Small-Cap Growth Fund, BMO Disciplined International Equity Fund, BMO Ultra Short Tax-Free Fund, and BMO Growth Allocation Fund approved the applicable reorganization. The joint meeting of shareholders was adjourned for the other Merging Funds in the table and will reconvene on January 7, 2022 for the consideration of the remaining proposed reorganizations. Pending shareholder approval, the anticipated merger date for the Merging Funds in the table below will be January 21, 2022.

FOR FINANCIAL PROFESSIONAL USE ONLY

115 S LaSalle St.

11^th Floor

Chicago, IL 60603

If you have any questions about this information, please call 1-844-BMO-FUND (266-3863).

All investments involve risk, including the possible loss of principal.

BMO Global Asset Management is the brand name for various affiliated entities of BMO Financial Group that provide investment management, retirement, and trust and custody services. Certain of the products and services offered under the brand name BMO Global Asset Management are designed specifically for various categories of investors in a number of different countries and regions and may not be available to all investors. Products and services are only offered to such investors in those countries and regions in accordance with applicable laws and regulations. BMO Financial Group is a service mark of Bank of Montreal (BMO).

Investment products are: NOT A DEPOSIT – NOT FDIC INSURED - NO BANK GUARANTEE – MAY LOSE VALUE

Investors should carefully consider the investment objectives, risks, charges and expenses of the BMO Funds. This and other important information is contained in the prospectuses and/or summary prospectuses, which can be obtained by calling 1-800-236-3863. Please read carefully before investing.

BMO Asset Management Corp. is the investment adviser to the BMO Funds. BMO Funds are distributed by Foreside Financial Services, LLC.

Important Additional Information and Where to Find It

BMO Funds, its directors and officers are deemed to be participants in the solicitation of proxies from BMO Funds’ shareholders in connection with the matters to be considered at the joint meeting of shareholders described herein. Information regarding the names of the directors and officers of BMO Funds, and their interests in BMO Funds by security holdings or otherwise, can be found in the most recent statement of additional information of BMO Funds, filed with the Securities and Exchange Commission (“SEC”) on July 6, 2021. A combined prospectus/proxy statement will be filed with the SEC in connection with the solicitation of proxies from BMO Funds’ shareholders in connection with each Plan of Reorganization and, as applicable, the new investment advisory and subadvisory agreements. SHAREHOLDERS ARE STRONGLY ENCOURAGED TO READ ANY SUCH PROSPECTUS/PROXY STATEMENT CAREFULLY AND IN ITS ENTIRETY WHEN IT BECOMES AVAILABLE, AS IT WILL CONTAIN IMPORTANT INFORMATION. Shareholders will be able to obtain copies of the combined prospectus/proxy statement and other documents filed by BMO Funds with the SEC for no charge at the SEC’s website at www.sec.gov. Copies will also be available at no charge by contacting BMO Funds’ proxy solicitor toll free at 888-991-1289.

FOR FINANCIAL PROFESSIONAL USE ONLY